Equal-Size Bins

One method of converting the measured data y1, y2, ..., yN into a symbol string i1, i2, ..., iN is first to find the range of the values, that is, the interval between the maximum (max) and the minimun (min) of the yi.
Next, divide the range (min, max) into four equal-size bins:
yk lies in bin1 if min ≤ yk < min + .25⋅(max - min)
yk lies in bin2 if min + .25⋅(max - min) ≤ yk < min + .50⋅(max - min)
yk lies in bin3 if min + .50⋅(max - min) ≤ yk < min + .75⋅(max - min)
yk lies in bin4 if min + .75⋅(max - min) ≤ yk ≤ max
The numbers separating the bins are called bin boundaries, B1, B2, and B3:
B3 = min + .75⋅(max - min)
B2 = min + .50⋅(max - min)
B1 = min + .25⋅(max - min)
Each yk lies in one of these bins, so we can convert the sequence y1, y2, y3 ... into the symbol string i1, i2, i3 ... of 1s, 2s, 3s, and 4s associated with the data. Here is an example.
ik = 4 if yk lies in bin4
ik = 3 if yk lies in bin3
ik = 2 if yk lies in bin2
ik = 1 if yk lies in bin1
Click on the picture to return.
Here is a time series generated by the logistic map, and the driven IFS produced using equal-size bins.

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